It is known from the state of the art that in 1900 an idea of a shaping reconfigurable die appeared. However, it was not until 1923 that William and Skiner registered a patent for “Spring Forming Devices” (U.S. Pat. No. 1,465,152) wherein a two-dimension device to form bellows was developed. This device consists of two manual-adjustment bolt columns that are smoothly distributed. Afterwards in 1931, Hess patented a kit of dies with highly dense elements (U.S. Pat. No. 1,826,783) used for metal sheet stamping. In 1943, Walter takes William and Skiner's idea and expands the die up to three dimensions by adding multiple bolt columns that conform to a metal sheet, and the bolt layer being opposed to each other and with manual type adjustment (U.S. Pat. No. 2,334,520).
In 1969, Nakajima publishes in the Mechanic and Engineer Japanese Society Bulletin, a development for a vertically oriented, re-configurable automatic die, with round bolts and positionable needles, which are mounted on the head of a numerical control turning machine to create serially the shape of a die. In 1973 Wolak J., under the Boeing company sponsorship, carried out a preliminary study of a variable surface generator to be used as a stretching forming die, but the idea was abandoned due to the lack of rigidity in the adjustable bolts.
By the late 70's and early 80's, inventor David Hardt from the Massachussets Institute of Technology developed a prototype of a re-configurable die by using computer-controlled servomotors for each individual actuator. In 1980, a discrete die, quite similar to Walters's design, was also developed, except that each bolt could be automatically adjusted by a computer through individual servomotors, with bolts separated from each other (U.S. Pat. No. 4,212,188). The Massachussets Institute of Technology also developed between 1985 and 1991 a shaping re-configurable die. This design automatically adjusted the die shape row by row, making a rigid die through a grasping mechanism. Later in 1991, Finckenstein and Kleiner developed a numerical control flexible machine with square bolts for deep die-pressing. In 1997 an article was published in “AEROSPACE AMERICA” magazine from a researcher, Flinn, E. D, reporting that DARPA (Defense Advanced Research Projects Agency) sponsored a program of re-configurable tools for flexible manufacturing, which was led by Northrop Grumman Corp company, because the aerospace industry requirements demanded low volumes and an unpredictable demand that required a reduction in tooling manufacturing costs and times. That die is activated by automatically controlled motors through a computer and is used to adjust bolt height. Inventor Im, Y.-T in 1998 developed a control system for a controlled re-configurable die, but used hydraulic cylinders.
In 1998 Walczyk, D. F., and Hardt, D. E developed a die for shaping by using computer-controlled hydraulic actuators, which consisted of square bolts that allow shaping of the sheet and the use of compound materials. Walczyk et al. demonstrated that a discrete die may be actuated by means of hydraulic cylinders. In 2002 Papazian et al., together with the United States Air Force Research Laboratory and Warner Robins Air Logistics Center, already developed an activated re-configurable system with servomotors and computer controls. That die has a system that reduced even more the re-configurability time, thus increasing the productivity thereof. However all the previously mentioned patents, as well as the technological developments, have a common problem. A very large bolt size is a limitation in this kind of tooling, because it only allows material shaping having a very coarse geometry. Another restriction regarding the bolt size is the manipulating actuator, which use servomotors and/or hydraulic cylinders.
Therefore the new invention herein proposed, a reconfigurable mechatronic system for shaping materials, significantly reduces the bolt size achieving an increase in bolt density per area unit to allow a large amount of pieces to be manufactured. Additionally, servomotors and hydraulic cylinders are substituted with functional materials, such as those known as memory effect materials. These materials serve as actuators, thus considerably reducing the size of the system.
However, the system may have a number of applications: as a guide for positioning, changing the surface or for shaping the generated surface, or a sheet for any pressure form, whether by a similar tool, by heat, by water, by oil, etc. The main feature of the mechatronic system in accordance with exemplary embodiments of the present invention is that each bolt is independently actuated, and that its position may be controlled to adopt any desired surface, which gives the system unique re-configurability features, those which are as fine as the bolt smallness and amount, which would be added to the mechatronic system. The control and movement of each bolt is carried out through a transmission mechanism and an actuator with a memory effect material in the shape of a wire or a plate.